Last night I noticed one of those little touches that drive home how detailed the underlying physics model is in LFS. I flipped my UF GTR onto its side and noticed in an external view that wheels which are freewheeling will gradually slow down and stop, presumably meaning that friction in the running gear is modeled. It looked very realistic. Who knows, maybe it happens in other sims too, I've just never noticed.

Hm, I actually had the impression mine were running forever, when I watched them once?

Perhaps it might slow and stop if the opposite wheel was stuck in the dirt and the LSD comes into play?

'Tis a thing I have noticed on occasion as well. I'm sure a certain amount of friction will be added when Scawen is ready to put it in.

Quote from Quietus :

Perhaps it might slow and stop if the opposite wheel was stuck in the dirt and the LSD comes into play?

Ah, you're right, that's probably what it was!

edit: it happens even when the car is on its back with both sets of wheels free to spin and it happens to both front and rear wheels. Since in the UFR the rear wheels are non-driven and are not connected via a diff, perhaps friction is modeled in the running gear after all.

Quote from BuddhaBing :

Ah, you're right, that's probably what it was!

edit: it happens even when the car is on its back with both sets of wheels free to spin and it happens to both front and rear wheels. Since in the UFR the rear wheels are non-driven and are not connected via a diff, perhaps friction is modeled in the running gear after all.

perhaps your brakes are always a tiny bit on !?
you really should check this as it could be slowing you down - I think you can use dxtweak or someting to fiz it if it the cause.

Another reason to love the LFS community.

At LFS someone suggests that LFS is overly complex (bearing friction), and we try to work out what he did wrong to get that effect (no offence mate). And in the process some informative and clever posts often turn up.

In other sims forums you suggest something is wrong and all hell breaks lose, but suggest something exists when it doesn't (such as a physics engine in rTractor), and they'll fight and shout that it does. And in the process trolls, mods and fools chip in with pointless comments.

Long Live Live For Speed

I've double- and triple-checked my axis settings and calibration using DxTweak2 and in-game, I've used the virtual pedals to check for background brake input and an external check of the brake lights shows that they are not engaged (I know the granularity of these last two tests isn't very accurate).

One possible factor here is that I use a clutch pedal and manual shifting but that shouldn't affect non-driven wheels. Yet, when I flip a car onto its back, the non-driven wheels slow to a stop by themselves and the driven wheels do the same if I disengage the clutch (there is some RPM even when the engine is idling so if the clutch is engaged the driven wheels will spin).

Can one or two of you guys do me a favour and do a quick double-check on your own systems to see if the non-driven wheels on a flipped car will continue to spin indefinitely if you don't apply brakes or whether they gradually slow down and stop? I'm using non-driven wheels to test since driven wheels have more confounding factors to consider. If so, I'm going to have to do some thorough troubleshooting of my controllers.

Thanks.

edit: I just did another couple of flip tests and this time one took over 3 minutes for the non-driven wheel to come to a complete stop. Three minutes is much longer than the other times but even so the wheels did stop eventually.

perpetuum mobile

Thanks for double-checking, Kev, it's very much appreciated. I am glad to hear that someone else is seeing the same thing, as it means I don't have to futz around with my controllers.

I would love to have seen the look on the face of anyone who walked in and interrupted you guys doing your "must roll car and time how long it takes for wheels to stop spinning" tests...

"What? This is physics, this! Wait! Where are you going? Custody of the kids? I'll see you in court!"

Tested it now, too.
Took about 4 minutes until they stopped.

It's just not really visible until they revolve in a speed where you can follow them.